The present disclosure relates to sealing mechanisms of automobile doors.
In a front door of an automobile illustrated in FIG. 1, a fixed pane is provided as a side panel 2 at the front of an up-and-down sliding window pane (hereinafter referred to as a sliding window pane) 1. Such a side panel 2 is used as a mirror base in some cases, and also called a corner bracket. Although not shown, in a rear door, a side panel is also provided at the rear of a sliding window pane in some cases. The side panel is not necessarily made of glass, and can be made of a metal or a resin.
A retainer 5 is fixed to the front door so as to hold the sliding window pane 1 while allowing the sliding window pane 1 to move up and down, and seal the clearance between the sliding window pane 1 and the side panel 2. A glass run is attached to the retainer 5. The retainer 5 and the glass run extend from below a belt line L of the door across the belt line L to reach the proximity of a front pillar.
FIG. 2 illustrates an example of a glass run 4. A first part 4a located at the upper end of the glass run 4 has a contact part 6 which comes in elastic contact with a weatherstrip on a front pillar when the door is opened or closed. A second part 4b continuous to the first part 4a has a hollow shape as illustrated in FIG. 3, for example, so as to seal the clearance between the sliding window pane 1 and the side panel 2. A third part 4c has an engagement part 7 to be engaged with a retainer 3. A fourth part 4d has an approximate U shape in cross section as illustrated in FIG. 4, for example, so as to hold the sliding window pane 1 while allowing the sliding window pane 1 to move up and down.
In this manner, since the parts of the glass run 4 have different shapes, formation of the glass run 4 employs an insert molding process in which previously molded parts are placed in a mold and then these parts are joined together, for example. In this process, the second part 4b and the fourth part 4d are prepared by extrusion molding, and are placed in a mold, and then, the first part 4a and the third part 4c are molded by injection or transfer. In this manner, the glass run 4 made of the integrated first through fourth parts 4a-4d is obtained.
In addition, a conventional technique of molding the first through third parts 4a-4c including the second part 4b at a time has also been studied. In this technique, since the second part 4b has a hollow shape, a core material (i.e., a core) is needed, and a slit for drawing out the core material needs to be provided in the second part 4b along the entire length thereof. However, if the slit for drawing out the core material in the second part 4b remains open, the retainer cannot stably hold the glass run, and the door glass panel is poorly sealed. As a solution to these problems, the slit for drawing out the core material is filled with an adhesive. In this case, however, when a load is applied to the adhesive, the adhesion might be broken. In addition, the adhesive might deteriorate with time. Thus, this solution is not effective.
In view of this, Japanese Utility Model Publication No. H03-5625 shows the following technique. In this technique, a hollow pad is inserted in a hollow weatherstrip having a longitudinally extending slit through the slit, and the slit is filled with an adhesive. In addition, if the slit is wide, the base of the hollow pad is fitted in the slit. Although not clearly described in this publication, the slit of this publication is supposed to be a slit for drawing out a core material described above.
According to the description of Japanese Utility Model Publication No. H03-5625, the rigidity of a glass run can be enhanced by the hollow pad. Thus, even in a case where an adhesive is applied to the slit, the adhesion is less likely to be broken. In addition, in a case where the base of the hollow pad is fitted in the slit, the glass run is expected to be more firmly held by a retainer because of the fitting of the hollow pad. However, there arises a problem of the necessity of another pad in order to prevent degradation of the glass-run holding ability by the slit and the sealing ability.